Keep new vegetable plants warm with row covers

Early spring is the perfect time to get spring vegetable gardens planted. The cool weather and lengthening days are ideal for growing short-season leafy greens like spinach, lettuce, mizuna, arugula, miner’s lettuce, orach, Japanese greens and Chinese cabbage. Longer-season spring vegetables like chard, onions, leeks, peas, kales, broccoli and cabbage can also be planted. Bucolic sunny days with temperatures in the 60s and 70s can get plants off to a great start. But night temperatures often dip into the low 40s or 30s. These temperature variations cause some plants to bolt (go to seed) prematurely, hold back growth or freeze in the case of non-hardy plants like lettuce. Night after night of frost is very hard on newly planted vegetables of any kind.

Row covers are an easy solution to this early spring weather situation, and also allow us to plant warm season vegetables early before the frost season is over.

The best row covers are a product called Reemay, a white spun polyester or polypropylene cloth-like material that allows light penetration of 70 to 80 percent, as well as air and rain. Reemay is often referred to as a floating row cover.

It does not need to be taken on and off and can remain on the beds continuously until you are ready to remove it permanently.

Many people use Reemay to cover their citrus in winter. Plastic coverings do not allow air circulation or water penetration and should be avoided.

Reemay is light and easy to use. It comes in several thicknesses, all of which confer a different degree of frost protection. But the lightest does a good job in all but the coldest areas, giving about 4 degrees of frost protection. Heavier thicknesses give slightly more protection and last longer, but reduce the amount of light that gets through.

Reemay is offered in 6-foot-wide rolls, which neatly cover an approximately 3-foot-wide bed, or you can buy wide sheets for wider beds and cut to fit.

Reemay can be laid only over the plants you want to protect and the edges secured by wire stakes or bricks so it doesn’t blow off. But the best way to use it is to make or buy hoops made from PVC pipe or steel that hold the Reemay suspended over the beds. These can be left on the beds from fall through spring.

Elevating the Reemay over the beds also creates a mini-greenhouse that plants absolutely thrive in. It moderates low temperatures and also protects the plants from bird, rabbit and insect predation.

Steel Hoops

Steep hoops are easy to make. Use cold-rolled steel one-quarter inch in size; 20-foot lengths can be purchased and (often) delivered from steel companies, or they may cut it to desired lengths for you.

One-quarter inch cold rolled steel cuts fairly easily with bolt cutters or a hacksaw. It is easy to bend to shape. For roughly 3-foot wide-beds, cut 20-foot lengths into three equal pieces, roughly 6-feet 7-inches each. For wider beds use longer pieces.

Entire 20-foot lengths can be used to make tunnels for blueberries, and covered with bird netting. Space hoops along the bed about 6 feet apart. Tie plastic string at ground level along the length of the bed (jute string stretches).

Throw the Reemay over the bed and even it out. Secure both ends first with bricks. Tuck the sides under the string and secure with clothespins or wire stakes.

You can tie a knot at both ends and secure with clothespins to the string or just use bricks. Leave this on until weather is settled, just flipping one side up to harvest.

If slugs are a problem, make sure to sprinkle some Sluggo around your plants before you put the Reemay on. Bird netting or shade cloth can also be used with the hoop row covers.

PVC Pipe Hoops

Use 201/2 to 203/4-inch PVC pipe as hoops. Use short pieces (about 1-foot) of rebar to put the ends of the pipe over. Pound these in the ground with a hammer so that about 6 inches remain above ground. Fit the ends of the PVC pipe over it. Rebar can be cut with a hacksaw. Use the same technique for securing the Reemay.

Galvanized Steel Row Cover Hoops

These can be purchased from various companies in different sizes. A typical size will be three-quarter-inch galvanized conduit steel pipe. But they vary. Steel row covers will last for many years.

Kate Frey’s column appears every other week in Sonoma Home. Contact Kate at: katebfrey@gmail.com, freygardens.com. On Twitter @katebfrey, Instagram @americangardenschool.